Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F255/00—Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00
  • C08F255/02—Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00 on to polymers of olefins having two or three carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L51/06—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B7/00—Insulated conductors or cables characterised by their form
  • H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
  • H01B7/29—Protection against damage caused by extremes of temperature or by flame
  • H01B7/295—Protection against damage caused by extremes of temperature or by flame using material resistant to flame
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/016—Flame-proofing or flame-retarding additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/20—Oxides; Hydroxides
  • C08K3/22—Oxides; Hydroxides of metals
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/24—Acids; Salts thereof
  • C08K3/26—Carbonates; Bicarbonates
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/38—Boron-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
  • C08L23/0807—Copolymers of ethene with unsaturated hydrocarbons only containing more than three carbon atoms
  • C08L23/0815—Copolymers of ethene with aliphatic 1-olefins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/16—Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers

Definitions

• This invention relates to jacketing material.
• the invention relates to jacketing material for wire and cable while in another aspect, the invention relates to jacketing material comprising, among other things, a halogen-free flame retardant, an ethylene-ethyl acrylate (EEA) or ethylene-butyl acrylate (EBA), and a homogeneous polyethylene.
• the invention relates to a jacketing material that exhibits good resistance to stress and/or thermal cracking.
• Polyolefin resins are commonly used as a material for the sheath layers, e.g., insulation, outer jacket, etc., of wires and cables.
• additives often must be blended with the polyolefin resins.
• These additives include organic halogenated compounds and flame retardant aids such as antimony trioxide.
• these additives can cause smoking and/or the emission of harmful gases when subjected to burning, and can also cause metals to corrode.
• halogenated flame retardant is often replaced with a non-halogenated flame retardant such as a metal hydroxide.
• a non-halogenated flame retardant such as a metal hydroxide.
• the use of a non-halogenated flame retardant has its own problems.
• One principal problem is that a considerable amount of non-halogenated flame retardant is necessary to achieve the same level of flame retardance as that achieved from using a halogenated flame retardant.
• This higher loading of flame retardant adversely affect the polyolefin resin in terms of extrudability, mechanical properties, flexibility, and low temperature performance, but it also increases the susceptibility of the polyolefin resin in the form of a wire or cable insulation or sheathing to stress and thermal cracking.
• Mg(OH) 2 magnesium hydroxide
• the cracking is sometimes attributable to large agglomerations of Mg(OH) 2 .
• Low cost Mg(OH) 2 typically are not surface coated, and thus have a relatively high surface energy (>90 mJ/m 2 ) and this, in turn, can result in a high level of agglomeration in the wire or cable insulation or sheath.
• Higher cost, surface coated Mg(OH) 2 is also known to crack in insulation or sheath layers comprising EEA.
• the invention is a wire or cable sheathing layer comprising (i) an non-halogenated flame retardant, e.g., aluminum trihydroxide (ATH), (ii) EEA or ethylene-butyl acrylate (EBA), (iii) a homogeneous polyethylene, (iv) a maleic anhydride (MAH) grafted polyethylene, (v) a silicone polymer, and (vi) optionally, a smoke suppressant, the insulation or sheathing layer exhibiting good resistance to stress and/or thermal cracking.
• an non-halogenated flame retardant e.g., aluminum trihydroxide (ATH), (ii) EEA or ethylene-butyl acrylate (EBA), (iii) a homogeneous polyethylene, (iv) a maleic anhydride (MAH) grafted polyethylene, (v) a silicone polymer, and (vi) optionally, a smoke suppressant, the insulation or sheathing layer exhibiting good resistance to
• the invention is a cable comprising at least one of (i) one or more electrical conductors or communications media, and (ii) a core of two or more electrical conductors or communications media, at least one of the electrical conductor, communications medium, or core being surrounded by a sheath or insulation layer comprising:
• the numerical ranges in this disclosure include all values from and including the lower and the upper values, in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value.
• a compositional, physical or other property such as, for example, molecular weight, viscosity, melt index, etc.
• a compositional, physical or other property such as, for example, molecular weight, viscosity, melt index, etc.
• Polymer means a polymeric compound prepared by polymerizing monomers, whether of the same or a different type.
• the generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term interpolymer as defined below.
• Interpolymer means a polymer prepared by the polymerization of at least two different types of monomers. This generic term includes copolymers, usually employed to refer to polymers prepared from two different types of monomers, and polymers prepared from more than two different types of monomers, e.g., terpolymers, tetrapolymers, etc.
• Blends mean a composition of two or more polymers. Such a blend may or may not be miscible. Such a blend may or may not be phase separated. Such a blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and any other method known in the art. Blends are not laminates.
• “Cable” and like terms mean at least one wire or optical fiber within a protective jacket or sheath.
• a cable is two or more wires or optical fibers bound together, typically in a common protective jacket or sheath.
• the individual wires or fibers inside the jacket may be bare, covered or insulated.
• Combination cables may contain both electrical wires and optical fibers.
• the cable, etc. can be designed for low, medium and high voltage applications. Typical cable designs are illustrated in U.S. Pat. Nos. 5,246,783, 5,889,087, 6,496,629 and 6,714,707.
• Sheath and like terms mean a protective wrapping, coating or other enveloping structure, usually polymeric in composition, about one or more wires or optical fibers.
• Insulation jackets are sheaths typically designed to protect to wires and/or optical fibers, or bundles of wires and/or optical fibers, from water and static electricity. Insulation jackets are usually, but not always, an interior component of a cable. Outer or protective jackets are sheaths typically designed as the outermost layer of a cable to provide the other components of the cable protection from the environment and physical insult. Outer jackets may also provide protection against static electricity.
• Core and like terms mean one or more wire or optical fiber, usually a bundle of wire and/or optical fibers, within a single sheath and that forms a central component of a cable.
• Each wire, optical fiber and/or bundle of wire and/or optical fiber within a core can be bare or enveloped with its own sheath.
• Density is determined in accordance with American Society for Testing and Materials (ASTM) procedure ASTM D792-00, Method B.
• Melt index (I 2 ) in g/10 min is measured using ASTM D-1238-04 (version C), Condition 190 C/2.16 kg.
• the notation “I 10 ” refers to a melt index, in g/10 min, measured using ASTM D-1238-04, Condition 190 C/10.0 kg.
• the notation “I 21 ” refers to a melt index, in g/10 min, measured using ASTM D-1238-04, Condition 190 C/21.6 kg.
• Polyethylene is typically measured at 190 C while polypropylene is typically measured at 230 C.
• DSC Differential Scanning Calorimetry
• TAI model Q1000 DSC equipped with an RCS cooling accessory and an auto-sampler.
• the apparatus is purged with a nitrogen gas flow (50 cc/min).
• the sample is pressed into a thin film and melted in the press at about 175 C and then air-cooled to room temperature (25 C).
• Material (3-10 mg) is then cut into a 3 mm diameter disk, accurately weighed, placed in a light aluminum pan (ca 50 mg), and then crimped shut.
• the thermal behavior of the sample is investigated with the following temperature profile.
• the sample is rapidly heated to 180 C and held isothermally for 3 minutes in order to remove any previous thermal history.
• the sample is then cooled to ⁇ 90 C at 10 C/min cooling rate and held at ⁇ 90 C for 3 minutes.
• the sample is then heated to 150 C at 10 C/min heating rate.
• the cooling and second heating curves are recorded.
• EEA and EBA i.e., the base resin (A) are copolymers comprising units derived from ethylene and one of ethyl acrylate and butyl acrylate, or both, using a conventional high pressure process and a free radical initiator, e.g., an organic peroxide, at a temperature in the range of 150 to 350 C and a pressure of 100 to 300 MegaPascal (MPa).
• the amount of units derived from ethyl acrylate or butyl acrylate, i.e., the comonomer, present in EEA or EBA is at least 5, and preferably at least 10, wt % based on the weight of the copolymer.
• the maximum amount of units derived from ethyl acrylate or butyl acrylate present in the copolymer typically does not exceed 40, and preferably does not exceed 35, wt % based on the weight of the copolymer.
• the EEA and EBA typically have a melt index (MI) in the range of 0.5 to 50 g/10 min.
• EEA and/or EBA is present in the composition is an amount of at least 15, preferably at least 17 and more preferably at least 18, wt % based on the weight of the composition.
• the maximum amount of base resin (A) present in the composition typically does not exceed 25, preferably it does not exceed 23 and more preferably it does not exceed 21, wt % based on the weight of the composition.
• Base resin (B) is a homogeneous polyethylene or a blend of two or more homogeneous polyethylenes. These homogeneous polyethylenes are copolymers of ethylene, one or more ⁇ -olefins and, optionally, a diene.
• the copolymer is a polymer formed from the polymerization of two or more monomers and includes terpolymers, tetramers and the like.
• the ⁇ -olefins can have 3 to 12 carbon atoms, preferably 3 to 8 carbon atoms.
• homogeneous interpolymers are interpolymers in which the comonomer is randomly distributed within a given interpolymer molecule and in which substantially all of the interpolymer molecules have the same ethylene/comonomer ratio within that interpolymer.
• heterogeneous interpolymers are interpolymers in which the interpolymer molecules do not have the same ethylene/comonomer ratio.
• the homogeneous polyethylenes are also characterized by single and relatively low DSC melting points. Homogeneous interpolymers are further described in U.S. Pat. No. 3,645,992.
• Examples of ⁇ -olefin comonomers include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene.
• the copolymers have a polydispersity (Mw/Mn) in the range of 1.5 to 3.5. Mw is defined as weight average molecular weight, and Mn is defined as number average molecular weight.
• the homogeneous polyethylenes can have a density in the range of 0.86 to 0.94 g/cc, preferably a density less than 0.90 g/cc.
• the preferred homogeneous polyethylenes for use in the practice of the invention have a density of less than 0.90 g/cc, an MI of 1 to 10 g/10 min, and a polydispersity of 3.3 or less.
• Homogeneous polyethylenes can be prepared, for example, with vanadium-based catalyst systems such as those described in U.S. Pat. Nos. 5,332,793 and 5,342,907. Homogeneous polyethylenes can also be prepared with single site metallocene catalyst systems such as those described in U.S. Pat. Nos. 4,937,299 and 5,317,036, and with constrained geometry catalysts such as those described in U.S. Pat. No. 6,538,070.
• homogeneously branched linear ethylene/ ⁇ -olefin interpolymers include the ENGAGETM and AFFINITYTM polymers available from The Dow Chemical Company, the TAFMERTM polymers supplied by the Mitsui Chemical Company, and the EXACTTM polymers supplied by ExxonMobil Chemical Company.
• the homogeneous polyethylene is present in the composition an amount of at least 5, preferably at least 7 and more preferably at least 8, wt % based on the weight of the composition.
• the maximum amount of the homogeneous polyethylene present in the composition typically does not exceed 15, preferably it does not exceed 13 and more preferably it does not exceed 12, wt % based on the weight of the composition.
• the ethylenic resin modified with an organo-functional group, i.e., base resin (C), of the present invention is obtained by modification of an ethylenic resin with a chemical compound containing an organo-functional group.
• An ethylenic resin is simply one wherein the primary monomer is ethylene.
• organo-functional group containing chemical compounds are unsaturated carboxylic acids such as fumaric acid, acrylic acid, maleic acid, crotonic acid and citraconic acid; unsaturated aliphatic diacid anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, 4-methyl cyclohexene-1,2-dicarboxylic anhydride, and 4-cyclohexene-1,2-dicarboxylic anhydride; epoxy compounds such as glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether; hydroxy compounds such as 2-hydroxyethyl acrylic acid, 2-hydroxyethyl methacrylic acid, and polyethylene glycol mono-acrylate; metal salts such as sodium acrylate, sodium methacrylate, and zinc acrylate; silane compounds such as vinyl tri-chloro silane, vinyl tri-ethoxy
• the ethylenic resins in unmodified form, can have a melt index in the range of 0.1 to 50 g/10 min and a density in the range of 0.86 to 0.95 g/cc. They can be any ethylene/ ⁇ -olefin copolymer produced by conventional methods using Ziegler-Natta catalyst systems, Phillips catalyst systems, or other transition metal catalyst systems.
• the copolymer can be a very low density polyethylene (VLDPE), ultra low density polyethylene (ULDPE), a linear low density polyethylene (LLDPE), a medium density polyethylene (MDPE) having a density in the range of 0.926 to 0.94 g/cc, or a high density polyethylene (HDPE) having a density greater than 0.94 g/cc.
• VLDPE very low density polyethylene
• ULDPE ultra low density polyethylene
• LLDPE linear low density polyethylene
• MDPE medium density polyethylene
• HDPE high density polyethylene
• ethylenic resins also include such resins as EVA, EEA, high pressure low density polyethylene (HP-LDPE, a homopolymer), or ethylene/ ⁇ -olefin copolymers produced by employing single site metallocene catalysts or CGCs.
• HP-LDPE high pressure low density polyethylene
• CGCs single site metallocene catalysts
• An amount of the above-mentioned organo-functional group containing chemical compound to be added to modify the ethylenic resin is preferably in the range of 0.05 to 10 wt % based on the weight of the resin.
• Modification can be accomplished by, for example, solution, suspension, or melting methods.
• the solution method comprises mixing an organo-functional group containing chemical, an ethylenic resin, a non-polar organic solvent and a free radical initiator such as an organic peroxide, and then heating the mixture to 100 to 160 C to perform the modification reaction.
• Hexane, heptane, benzene, toluene, xylene, chlorobenzene and tetra-chloroethane are examples of non-polar solvents.
• 2,5-dimethyl-2,5-di(t-butyl peroxy) hexane, 2,5-dimethyl-2,5-di(t-butyl peroxy) hexyne-3, and benzoyl peroxide are examples of organic peroxides.
• the ethylenic resin, the organo-functional group containing chemical compound and a free radical initiator are introduced into a melting-kneading machine such as an extruder and BANBURYTM mixer to obtain the modified ethylenic resin.
• the modified polymer e.g., an anhydride grafted polymer
• Anhydride modification can be accomplished by, for example, the copolymerization ethylene and maleic anhydride, and optionally comonomers such as ethyl acrylate.
• the polymerization technique is a conventional high pressure polymerization of the underlying comonomers.
• Maleic Anhydride Trivedi et al, Polonium Press, New York, 1982, Chapter 3, section 3-2. This treatise also covers grafting.
• the ethylenic resin modified with an organo-functional group is present in the composition is an amount of at least 3, preferably at least 4 and more preferably at least 5, wt % based on the weight of the composition.
• the maximum amount of base resin (C) present in the composition typically does not exceed 12, preferably it does not exceed 10 and more preferably it does not exceed 8, wt % based on the weight of the composition.
• non-halogenated flame-retardant i.e., component (D) employed in the present invention
• component (D) examples include: ATH, red phosphorous, silica, alumina, titanium oxide, carbon nanotubes, talc, clay, organo-modified clay, calcium carbonate, zinc borate, antimony trioxide, wollastonite, mica, ammonium octamolybdate, frits, hollow glass microspheres, intumescent compounds and expanded graphite.
• the preferred non-halogenated flame retardant is ATH.
• the non-halogenated flame retardant is present in the composition is an amount of at least 40, preferably at least 45 and more preferably at least 50, wt % based on the weight of the composition.
• the maximum amount of non-halogenated flame retardant present in the composition typically does not exceed 65, preferably it does not exceed 60 and more preferably it does not exceed 55, wt % based on the weight of the composition.
• the non-halogenated flame retardant can be surface treated (coated) with a saturated or unsaturated carboxylic acid having about 8 to about 24 carbon atoms and preferably about 12 to about 18 carbon atoms or a metal salt of the acid, but a coating is optional.
• a saturated or unsaturated carboxylic acid having about 8 to about 24 carbon atoms and preferably about 12 to about 18 carbon atoms or a metal salt of the acid, but a coating is optional.
• suitable carboxylic acids are oleic, stearic, palmitic, isostearic, and lauric
• of metals which can be used to form the salts of these acids are zinc, aluminum, calcium, magnesium, and barium
• of the salts themselves are magnesium stearate, zinc oleate, calcium palmitate, magnesium oleate, and aluminum stearate.
• the amount of acid or salt can be in the range of 0.1 to 5 parts of acid and/or salt per one hundred parts of metal hydrate and is preferably 0.25 to 3 parts per one hundred parts of metal hydrate.
• the surface treatment is described in U.S. Pat. No. 4,255,303.
• the acid or salt can be merely added to the composition in like amounts rather than using the surface treatment procedure, but this is not preferred.
• Other surface treatments known in the art may also be used including silanes, titanates, phosphates and zirconates.
• silicone polymer i.e., component (E) employed in the invention is exemplified by the following formula:
• each R is independently a saturated or unsaturated alkyl group, an aryl group, or a hydrogen atom, and n is 1 to 5000.
• Typical R groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, phenyl and vinyl.
• R is methyl.
• the silicone can also be a silicate, silicone oil or the like, and examples of these include glycidyl-modified silicate, amino-modified silicate, mercapto-modified silicate, polyether-modified silicate, carboxylic acid modified silicate, or higher fatty acid modified silicate.
• the viscosity of the silicone polymer can be in the range of 1,000 to 100,000,000 centistokes at 23 C.
• the viscosities of the silicones are preferably above 5,000,000 centistokes, and most preferably above 10,000,000 centistokes at room temperature (23 C).
• Silicone polymer is present in the composition is an amount of at least 1, preferably at least 2 and more preferably at least 3, wt % based on the weight of the composition.
• the maximum amount of silicone polymer present in the composition typically does not exceed 8, preferably it does not exceed 7 and more preferably it does not exceed 6, wt % based on the weight of the composition.
• the smoke suppressant i.e., optional component (F) effectively reduces the amount of aromatic species released as smoke by promoting char development during a fire.
• Commercial smoke suppressants include various forms of zinc borate, magnesium/zinc/antimony complexes, magnesium/zinc complexes and anhydrous sodium antimonates all available from GLCC Laurel, LLC.
• Smoke suppressant (F) is optional in the compositions of the present inventions but if it is present, then it is present an amount of at least 1, preferably at least 3 and more preferably at least 5, wt % based on the weight of the composition.
• the maximum amount of smoke suppressant present in the composition typically does not exceed 20, preferably it does not exceed 15 and more preferably it does not exceed 10, wt % based on the weight of the composition.
• the preferred smoke suppressant is magnesium hydroxide (which forms MgO during combustion) since the magnesium hydroxide also contributes as a flame retardant.
• the resin components of this invention i.e., components (A), (B) and (C) can be combined with conventional additives provided that the particular additive chosen will not adversely affect the composition.
• the additives can be added to the resin composition prior to or during the mixing of the components, or prior to or during extrusion.
• the additives include antioxidants, ultraviolet absorbers or stabilizers, antistatic agents, pigments, dyes, nucleating agents, reinforcing fillers or polymer additives, resistivity modifiers such as carbon black, slip agents, plasticizers, processing aids, lubricants, viscosity control agents, tackifiers, anti-blocking agents, surfactants, extender oils, metal deactivators, voltage stabilizers, fillers, flame retardant additives, and crosslinking boosters and catalysts.
• Additives can be added in amounts ranging from less than 0.1 to more than 5 parts by weight for each 100 parts by weight of the resin. Fillers are generally added in larger amounts up to 200 parts by weight or more.
• antioxidants are: hindered and semi-hindered phenols such as tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]-methane, bis[(beta-(3,5-ditert-butyl-4-hydroxybenzyl)-methylcarboxyethyl)]sulphide, 4,4′-thiobis(2-methyl-6-tert-butylphenol), 4,4′-thiobis(2-tert-butyl-5-methylphenol), 2,2′-thiobis(4-methyl-6-tert-butylphenol), and thiodiethylene bis(3,5-di-tert-butyl-4-hydroxy)hydrocinnamate; phosphites and phosphonites such as tris(2,4-di-tert-butylphenyl)phosphite and di-tert-butylphenyl-phosphonite; thio compounds such as dilaurylthio
• the various resins can be crosslinked in a conventional manner, if desired.
• Crosslinking is usually accomplished with organic peroxide, examples of which are mentioned with respect to grafting.
• the amount of crosslinking agent used can be in the range of 0.5 to 4 parts by weight of organic peroxide for each 100 parts by weight of resin, and is preferably in the range of 1 to 3 parts by weight.
• Crosslinking can also be effected with irradiation or moisture, or in a mold, according to known techniques.
• Peroxide crosslinking temperatures can be in the range of 150 to 210 C and are preferably in the range of 170 to 210 C.
• the resins can also be made hydrolyzable so that they can be moisture cured. This is accomplished by grafting the resin with, for example, an alkenyl trialkoxy silane in the presence of an organic peroxide (examples are mentioned above), which acts as a free radical generator.
• an alkenyl trialkoxy silane include the vinyl trialkoxy silanes such as vinyl trimethoxy silane and vinyl triethoxy silane.
• the alkenyl and alkoxy radicals can have 1 to 30 carbon atoms and preferably have 1 to 12 carbon atoms.
• the hydrolyzable polymers are moisture cured in the presence of a silanol condensation catalyst such as dibutyl tin dilaurate, dioctyl tin maleate, stannous acetate, stannous octoate, lead naphthenate, zinc octoate, iron 2-ethyl hexoate, and other metal carboxylates.
• a silanol condensation catalyst such as dibutyl tin dilaurate, dioctyl tin maleate, stannous acetate, stannous octoate, lead naphthenate, zinc octoate, iron 2-ethyl hexoate, and other metal carboxylates.
• the organic peroxides can be the same as those mentioned above for crosslinking.
• composition can also be blended and kneaded using a BANBURYTM mixer, a HENSCHELTM mixer, a kneader, a multi-screw extruder, or continuous mixer to obtain a uniformly compounded composition.
• the resin composition can be mixed and the cable coated with the resin composition can be prepared in various types of extruders, some of which are described in U.S. Pat. Nos. 4,814,135, 4,857,600, 5,076,988 and 5,153,382.
• a variety of types of single screw and twin screw extruders and polymer melt pumps and extrusion processes will generally be suitable in effecting the process of this invention.
• a typical extruder commonly referred to as a fabrication extruder, will have a solids feed hopper at its upstream end and a melt forming die at its downstream end. The hopper feeds unfluxed plastics into the feed section of a barrel containing the processing screw(s) that flux and ultimately pump the plastic melt through the forming die.
• Fabrication extruders typically accomplish the mechanisms of solids conveying and compression, plastics fluxing, melt mixing and melt pumping although some two stage configurations use a separate melt fed extruder or melt pump equipment for the melt pumping mechanism.
• Extruder barrels are equipped with barrel heating and cooling features for startup and improved steady state temperature control. Modern equipment usually incorporates multiple heating/cooling zones starting at the rear feed zone and segmenting the barrel and downstream shaping die. The length to diameter ratio of each barrel is in the range of 15:1 to 30:1.
• the advantages of the invention lie in a relatively low amount of inorganic flame retardant, excellent flame- and heat-resistance, mechanical properties superior to conventional products, good moldability, good low temperature performance, good processability and flexibility, essentially no emission of harmful gases such as halogen, and good stress/thermal resistance to cracking.
• the subject cable comprises one or more electrical conductors or communications media, or a core of two or more electrical conductors or communications media, in which at least one, preferably each, electrical conductor, communications medium, or core is surrounded by a sheath or an insulation layer comprising a composition of the present invention.
• the electrical conductors are generally copper or aluminum and the communications media are generally fiber optics made of glass fibers.
• AMPLIFY EA 100 is an ethylene ethyl acrylate copolymer (i) comprising 15 wt % units derived from ethyl acrylate, and (ii) having a density of 0.932 g/cc, and a melt mass-flow rate (MFR, ASTM D1238 at 190 C/2.16 kg) of 1.3 g/10 min.
• AMPLIFY GR 208 is a post-reactor, MAH-grafted ethylene-butene copolymer.
• the copolymer has a density of 0.904 g/cc, and an MFR of 3.3 g/10 min.
• AFFINITY KC 8852G is an ethylene-octene copolymer (i) produced by constrained geometry catalysis, and (ii) having a density of 0.877 g/cc, and an MFR of 3 g/10 min.
• AFFINITY EG 8100G is an ethylene-octene copolymer (i) produced by constrained geometry catalysis, and (ii) having a density of 0.872 g/cc, and an MFR of 1 g/10 min.
• AFFINITY PL 1850G is an ethylene- ⁇ -olefin copolymer (i) produced by constrained geometry catalysis, and (ii) having a density of 0.904 g/cc, and an MFR of 3 g/10 min.
• AFFINITY PL 1880G is an ethylene- ⁇ -olefin copolymer (i) produced by constrained geometry catalysis, and (ii) having a density of 0.904 g/cc, and an MFR of 1 g/10 min.
• ENGAGE ENR 7380.00 is an ethylene-butene copolymer with a density of 0.872 and an MFR of 0.5 g/10 min.
• ENGAGE ENR 7360.00 is an ethylene-butene copolymer with a density of 0.875 and an MFR of 1 g/10 min.
• HUBERCARB G3T is calcium carbonate (3 micron average particle size) available from J.M. Huber Corporation and comprising a surface treatment of 0.75 to 1.5 percent stearic acid.
• ALMATIS HYDRAL PGA is aluminum trihydroxide or (ATH) (1.6 micron average particle size) available from Mineral and Pigment Solutions, Inc.
• FR-20-S10 is uncoated magnesium hydroxide with a surface area of 10 m 2 /g and available from Dead Sea Bromine Group.
• VERTEX 60 is an uncoated grade of magnesium hydroxide with an average particle size of 1.5 micron and available from J.M. Huber Corporation.
• VERTEX 60ST is an uncoated grade of magnesium hydroxide with an average particle size of 1.5 micron and available from J.M. Huber Corporation and comprising a surface treatment of a fatty acid.
• KISUMA 5B-1G is magnesium hydroxide coated with oleic acid and with an average particle size of 0.65 micron available from Kyowa Chemical Industry Co., Ltd.
• MAGSHIELD UF is a magnesium hydroxide with a stearate coating, and it is available from Martin Marietta Magnesia Specialties.
• INDUSTRENE 5016 is stearic acid available from Chemtura.
• MB50-320 masterbatch is a pelletized formulation containing 50% of an ultra-high molecular weight siloxane polymer dispersed in EVA polymer. It is available from Dow Corning Corporation.
• IRGANOX 1010 is a hindered phenol based antioxidant available from Ciba Specialty Chemicals.
• Table 1 reports that formulations using Mg(OH) 2 as the filler in an EEA/single-site elastomer matrix results in thermal/stress cracking, while surprisingly both the CaCO 3 and ATH formulations did not crack.
• the use of ATH or blend of ATH/CaCO 3 is preferred over CaCO 3 because of the better inherent flame retardation properties. While not wanting to be bound to theory, the cracking may be attributed to large agglomerates of Mg(OH) 2 compared to ATH, as shown in Table 1.

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• 2008
  • 2008-02-20 CN CN200880015278A patent/CN101679672A/zh active Pending
  • 2008-02-20 EP EP08730239A patent/EP2134778A1/en not_active Withdrawn
  • 2008-02-20 JP JP2009552794A patent/JP2010520937A/ja not_active Withdrawn
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  • 2008-02-20 US US12/529,480 patent/US20100101822A1/en not_active Abandoned
  • 2008-02-20 WO PCT/US2008/054398 patent/WO2008112393A1/en active Application Filing
  • 2008-02-20 CA CA002679916A patent/CA2679916A1/en not_active Abandoned
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